The following U.S. Patents are incorporated herein by reference in entirety:
U.S. Pat. No. 2,627,242 discloses an outboard motor adapted to be secured to the transom of a boat. The outboard motor has an engine, a housing supporting the engine, a propeller carried by the housing, an exhaust chamber in the housing to receive exhaust gases directly from the engine, and an underwater exhaust opening positioned rearwardly of the adjacent propeller. The chamber in normal operation of the engine is subject to substantially less than atmospheric pressure. A conduit having one end open at the bottom of the boat communicates with the chamber. The conduit is adapted to extend and permit the motor to be freely pivoted for steering and raising from the water.
U.S. Pat. No. 4,403,972 discloses a marine propulsion device that includes a housing surrounding an engine and including a sump which may collect water. A siphon conduit is provided for removing water from the sump, the siphon conduit including an inlet end housed in the sump and a discharge end projecting from the housing for discharging water from the sump. Another conduit is connected to the siphon conduit and for generating water flow through the siphon conduit from the sump and toward the siphon conduit discharge end, this second conduit being connected to the engine water pump and adapted to force a jet of water into the siphon conduit and toward the discharge end of the siphon conduit.